You might want to put down that glass of water for this next segment. The Associated Press reported that, quote, "a vast array of pharmaceuticals -including antibiotics, anticonvulsants, mood stabilizers, and sex hormones -have been found in the drinking water supplies of at least 42 million Americans." Now, before you get worried, there isn't much of this stuff in the drinking water, just a few parts per billion - in a few cases per million. Still, the report does raise questions about how clean and safe our drinking water is. And the report's getting a lot of coverage today in the media.

If you have a question about drinking water safety and what effect, if any, trace amounts of pharmaceuticals might have, give us a call. 800-989-8255. Our e-mail address is talk@npr.org. And you could comment on our blog at npr.org/blogofthenation.

Joan Rose is a professor at Michigan State University where she holds the Homer Nowlin Water Chair in Water Research. She joins us now from the studios of member station WKAR in East Lansing, Michigan. Good to have you with us.

Dr. JOAN ROSE (Homer Nowlin Chair in Water Research, Michigan State University): Thank you. It's good to be here.

SMITH: Well, let's get into this. How big a deal is this trace amounts of prescription drugs in the water?

Dr. ROSE: Well, we've known and been testing for these drugs for some time, and I think the first broad survey was published in 2002 by USGS scientists. I think what it points out is this close connection we're starting to have between our wastewater - our human waste and even our animal waste - and our drinking water supply. And so that short-circuiting of the natural environment leads one to be concerned.

SMITH: Well, how long have we known that what we ingest can make it through and into the water? I remember about five, six years ago - maybe more - when I lived in Seattle, there was a report on the high caffeine levels in Elliott Bay off the coast of Seattle there. Of course, the coffee-drinking culture there. The caffeine was passing through the urine and caffeinating the fish and the giant squid in Elliott Bay. Have we known for a long time that this can affect our water supply?

Dr. ROSE: Yes. We've known for some time that what we discharge upstream could affect our water supply. I think that the water industry has always looked at this as sort of a multi - producing sort of a multi-barrier approach. That is, if we protect our watershed where we take our water from and then we have multiple-treatment approaches to reduce the contaminants of concern. I think one of the things we've learned is that we need to do a lot more monitoring particularly of these emerging contaminants. Over the last decade, we have new types of microorganisms and chemicals that come from the waste stream, and as our wastewater gets closer and closer to our drinking water supplies because of more people and more animal wastes and poor infrastructure, I think we have to worry more and more about these new and emerging microbial and chemical contaminants.

SMITH: Now, isn't all these stuff filtered out? That's what we sort of thought.

Dr. ROSE: Well, I think there's a number of barriers. In the wastewater treatment plants itself, our activated-sludge processes can reduce some of these contaminants. But some are quite recalcitrant on - depending on how well we disinfect that wastewater, we may have a number of viruses and other types of contaminants that can pass by the oxidation process. In the drinking water process itself, we also have filtration and disinfection in a normal drinking water plant. And these two act as barriers, but they can't get everything.

And as you can see by the survey in the studies, very small amounts of these contaminants are in our water supplies. So it's very, very widespread in the waters that we use for drinking, but when we get to monitoring our drinking water itself, at the tap, we don't find it very often.

SMITH: Now, is that a matter of how hard we're looking? I mean, some water industry people have said the only reason this is showing up now is not necessarily because we're using a lot more drugs - although I suppose we are - but because our techniques for finding such trace chemicals are getting better, and so in that case, its not a crisis, it's just a better monitoring of the water system.

Dr. ROSE: I think that's partly true. I think we are bringing better methods and new methods for these contaminants. If you look at the, sort of the risk paradigm, there's two sides to it. One is, are we being exposed? Are we being exposed to things that perhaps on a routine basis that we shouldn't be exposed to? And then, how much are we being exposed to, how often and what concentrations? And then on the other side, what do we know about the health risks? And I think that we certainly need to spend more time on the exposure side. We need to understand more about that monitoring. As that information comes to light, it certainly pushes us towards the other side of the equation - trying to understand what are the health impacts of this type of exposure.

SMITH: Sure, we're always talking about drug interactions when you get prescriptions, we just didn't know it would be happening in our streams, lakes and our drinking water. Let's go now to Darrel(ph). Darrel's calling us from Phoenix, Arizona. Darrell?

DARREL (Caller): Well, hi. How are you guys?

SMITH: Good. Go ahead.

DARREL: Well, you know, I'm really upset about our government here in Phoenix, and I'm wondering what we can do as citizens to get them to take a good look. Tucson checks, Phoenix doesn't. And Tucson found stuff, I'm sure Phoenix would too.

SMITH: What do you think, Joan Rose, is it sort of better to know, better to get your community to check or, maybe ignorance is bliss in some of these places?

Dr. ROSE: Yeah, you know, it's sort of a double-edged sword, that is if you start looking for things and you're starting to use better methods - I think it has already been mentioned, you'll find it. But I am a big believer in monitoring and sampling, and for the water industry to do the best they can in interaction with health departments and their community in letting them know what's going on. So part of it is public assurances. There's always one of those things where how many samples do you take and you show the negative, you saw zero, zero, zero everyday, and then one day out of the year you find a positive and you have to talk about what that positive means and what you're doing about it. And so, I think that we need more of that discussion. I do think that the water industry is recalcitrant to monitoring…

DARRELL: Yes.

Dr. ROSE: …particularly when they don't have a good way of explaining it, perhaps, to the public.

SMITH: Thanks for your phone call, Darrel. It is a good question about how often you monitor because I'm sure there's seasons for this like everything else. There's got to be a Prozac season around the holidays and maybe an amphetamine season and caffeine, of course, year-round. Let's go to Raymond(ph) in Portland, Oregon who has a question.

RAYMOND (Caller): Hello, thanks for taking my call. I'm a hospice nurse, a home health nurse, and at the time of our patient's deaths we're told no longer to flush the medications down the toilet, but to put them in kitty litter or coffee grounds and throw them in the garbage. And my question is, is this futile? Isn't the - aren't the medications finding their way into the groundwater from landfill?

SMITH: Very interesting. Coffee grounds, does that work? Joan, what do you think?

Dr. ROSE: Yes, well, modern landfills, of course, are lined and they try to protect any transport of what might be in a landfill through the soil system into the groundwater. But, of course, there's the concern of some of the older landfills. And then there's the choice of what are we going to do with our solid waste or these types of wastes if we're not going to put them in landfills, and incineration is one approach. And then, of course, you have to look at what might be released in the air. So I think, more and more, though, pharmacies and doctors and water utilities are coming together and public health industry is coming together and suggesting that you no longer flush your medicines down the toilet, that there be a return system or a way to put them into the trash in a safe manner.

WALTER: I'm curious about not only what accidentally or unintentionally gets put into the water system but what purposefully gets put in the water system. I'm a - pretty much wished that I didn't have to have fluoride in our public water system. And my question specifically is, I've been told that reverse osmosis system can eliminate even fluoride, is it possible that it could eliminate other things like these as well?

SMITH: What do you think, Joan? Is that — what does reverse filtration do? What can we do? What can get out and what stays?

Dr. ROSE: Yeah. So reverse osmosis is a process in which a very small membrane, a tiny, tiny filter, keeps some of everything else out except for water. Now there are small organics that can get through the membrane filter. And in fact, some water utilities are starting to use these processes in their full-scale water treatment plants. They're starting to use microfiltration and reverse osmosis. And even at advanced waste water treatment facilities, they're using these processes along with advanced oxidation and this can remove a whole range of these contaminants.

Now, if we put these things at our tap, there's a couple of things about point-of-use devices that we might want to think about. Obviously, you know, there are a lot of different choices for point-of-use devices, so you want to get one that you know has been rated and tested and removes things that you might have a concern about. Lead is one that has been very important because, we might have an old house with lead soldering and we can use a treatment process at out tap to take the lead out of our drinking water.

And so I think it is important that you know what kind of treatment device you're getting and what you want to take out. And secondly, that it's maintained properly, because then it's going to be up to the homeowner to make sure that they replace it and maintain it properly and follow the manufacturer's instructions. But generally, these membrane processes are ones which can work quite well.

SMITH: Thank you very much for your phone call, Walter.

WALTER: Thank you.

SMITH: You're listening to TALK OF THE NATION from NPR News. Let's go to Paul(ph) now. Paul is calling us from Phoenix, Arizona. Paul?

PAUL (Caller): Hello?

SMITH: Hello, Paul, you are on the air.

PAUL: Hi. Thanks for taking my call. I really have just a two-part comment. I like the answer on the air, too, because I'm (unintelligible) by a vehicle right now. But my first comment is that I'm wondering how long have I been exposed to this and is there any long-term effects that could possibly be like, from having a little bit of this medication in your system over a long period of time? And my second comment is that the media down here in Phoenix, they really kind of done a scare tactic thing last night. I was watching the news and they said it like, the water might be contaminated with this, you know, medication and what not, and, you know, I come listening to you guys today and its like a part-per-million. I'm not really that worried about that. And I was just wondering what you guys thought?

SMITH: What do you think Professor Joan Rose, is this something to worry about?

Dr. ROSE: Well, I think that - if you look at the studies, most of them have been focused on the water supply, that is our surface waters and some of our ground waters that come in to our treatment plants. And again, yes, these are at very, very low concentrations. And, in fact, they are thousands - hundreds of thousands - of times below the therapeutic dose that we would normally take. Now, I think that all of us in our communities have different levels of a sense of risk in this regard. And so there — I think there are some people that are going to feel more concerned about this, maybe some of the sensitive populations, because we know some drugs might be problematic for the elderly or for young children or pregnant women, and there's others that are going to feel that these low, low levels, we've probably been exposed to them through a variety of means in over a long period of time and we shouldn't worry too much.

I think that really the truth lies in between those. I think that the water industry is interested in knowing what is in their water supply and what is in their treated drinking water and they want to do their utmost to protect their watershed, treat the water, and provide safe what, you know, what the current yardstick is for safe water at the tap. When we find out about these new things, I think the best we can do is start to monitor, work with public health and the community, and begin to talk about it like we are now. And I think we will have to watch and see whether there's a risk for sensitive populations. It's very, very difficult when you start talking about long term exposure over a lifetime to know whether these low-level exposures are a problem. And so we're going to have to invest in long-term surveillance of our public health.

SMITH: We have time for one more caller. We are going to go to Ingrid(ph) in Lafayette, Colorado. Thanks for calling, Ingrid.

INGRID (Caller): Hi.

SMITH: Go ahead.

INGRID: Yes, hello.

Dr. ROSE: Hi.

SMITH: Go ahead with your question.

INGRID: What I'm wondering is about alternatives for consumers. If we heard today that bottled water is a better option, isn't a lot of bottled water, acknowledged by the companies, to be tap water that's been filtered?

SMITH: What about that Joan Rose. Is it any better to drink from bottled water? And then, how do we know?

Dr. ROSE: You know, every state takes a look at bottled water a little bit differently. If you look on the label, if you're in a state where bottled water is labeled, and certainly the industry supports this, it'll tell you where the water comes from, how much more it's treated. Sometimes, bottled water undergoes, even though it's using tap water, it undergoes extra filtration like membrane processes, the reverse osmosis that we were talking about before. That may be on the label. However, of course, we have to consider that all the water we're using in our foods, in our various types of beverages, and at the tap, all comes from similar sources.

So I think one of our goals is to look at our watersheds and make sure we're protecting our watersheds. I think this means we are going to have to go back to out wastewater infrastructure and look at how well we're treating both animal and human waste and protecting that watershed. Is bottled water a better alternative? I think the consumer will have to look very carefully at the label and look at how it's treated and then make a decision. But I think everybody in every community should also support their local water community supply, because, of course, you're showering in that water, you recreate in that water and you drink that water.

SMITH: Absolutely. Joan Rose is the director of The Center for Water Sciences at Michigan State University. She joined us from the studios of member station WKAR in East Lansing, Michigan. Thanks so much.

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